Influence of V2O5 additions to NdAlO3 ceramics on sintering temperature and microwave dielectric properties

The effects of sintering aids addition on the microstructures and microwave dielectric properties of NdAlO3 ceramics were investigated. V2O5 was selected as liquid phase sintering aid to lower the sintering temperature of NdAlO3 ceramics. With V2O5 addition, the densification temperature of NdAlO3 can be effectively reduced from 1650 °C to 1390∼1410 °C. The crystalline phase exhibited no phase differences at low addition level while Nd4Al2O9 and NdAl11O18 present as second phases as the addition level was over 1 wt.%. The quality factor Q×f was strongly dependent upon the amount of additions. Q×f values of 64,000 GHz and 48,000 GHz could be obtained at 1390∼1410 °C with 0.25 wt.% and 0.5 wt.% V2O5 addition, respectively. During all addition ranges, the relative dielectric constants were not significantly different and ranged from 21.6 to 22.5.The temperature coefficients varies from –31∼–43 ppm/°C.